Home > Publications database > Columnar Structured Thermal Barrier Coatings Deposited by Axial Suspension Plasma Spraying |
Book/Dissertation / PhD Thesis | FZJ-2019-02822 |
2019
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
Jülich
ISBN: 978-3-95806-391-4
Please use a persistent id in citations: http://hdl.handle.net/2128/22148
Abstract: Thermal Barrier Coatings (TBCs) providing thermal insulation for underlying metalliccomponents are widely used in turbine engines. Suspension Plasma Spraying (SPS) is apromising technology to produce TBCs. With it, a variety of microstructures can be achieved.Especially columnar structured coatings with high strain tolerance have great potentials as TBCs.Thus the potentials of SPS coatings as TBCs were explored in this work.In this work, potentials of SPS coatings were discussed with four parts, respectively. In the firstpart, relationships between spraying parameters, microstructures, mechanical properties andthermal cycling lifetime were preliminarily explored. It was found that spraying parametersespecially spraying distance and bond coat roughness greatly affected the microstructures ofcoatings. A simplified model was built to correlate the mechanical properties to the thermalcycling lifetime.Even though mechanical properties of coatings were optimized in the first part, the lifetime ofSPS coatings was still short compared with APS coatings. Therefore, in the second part, a failuremechanism for columnar SPS coatings was promoted. According to this failure mechanism, twoarchitecture designs were promoted. With the new architectures, the lifetime of SPS coatingswas greatly improved.Sintering behavior of columnar TBCs produced with SPS was discussed in the third part.Annealing resulted in obvious modifications on the microstructure of the coatings. Thesemodifications also led to changes in mechanical properties. It was found that by short time preannealing,thermal cycling lifetime of coating could be significantly improved.In the last part, thermal cycling performances of multilayered GZO/YSZ coatings were discussed.These multilayered coatings exhibited excellent thermal cycling performances which could beattributed to their higher strain tolerance and better sintering resistance.In summary, SPS is a very promising technology for applying the top coat of TBCs; however,further researches are needed to get a full understanding of this type of coatings
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